There have been numerous bizarre nutritional regimes over the years, though none quite as unwholesome as William Leith's pencil-case diet. As an unhappy, corpulent boarding-school pupil, Leith not only chewed through everything in the pantry but began to raid the contents of the stationery cupboard as well.

With hindsight one might recognise that a 13-year-old boy with a mouth full of ink was crying out for attention, and this book is essentially that cry writ large. Part memoir, part slimmer's diary, part recipe book, it's an entertaining, if slightly painful, exhibition of comic self-abasement at the expense of the chubbiest kid in class.

Leith, who admits to having once spooned down an entire jar of coffee creamer in one go, has fought a losing battle against his raging appetite throughout his life. He feels intimidated by the ubiquity of men's health publications, which he calls stomach magazines, because he cannot stomach them. But most of all he despises "fat people and their excuses ... the whiny fat pigs. Why don't they just stop whining and do something about it? Why don't I just stop whining and do something about it?"

An answer of sorts comes with Leith's decision to try the low-carbohydrate, high-protein regime advocated by the controversial American nutritionist Dr Robert Atkins. Like many people embarking on a weight-loss programme, Leith studies the alternatives and concludes that they sound too much like hard work. The F-plan he rejects as too wholesomely astringent, while the food combination principle of the Hay is compromised by the fact that you have to look at your food, "which makes it harder to watch TV and eat at the same time".

Atkins offers the kind of regime Leith believes he can get along with, however: a dairy-rich diet for affluent folk who don't fancy much exercise. He even boards a plane to interview the diet guru in person, and then, rather disconcertingly, is commissioned to turn the piece into an obituary when the doctor collapses outside his office barely six weeks later.

Leith is no stranger to the art of turning out a sardonic, self-referential newspaper column, and his prose has the confident, ringing sound of a man used to hitting nails smartly on the head. Making the link between the erotic shortcomings of pornography and the nutritional deficiency of snack foods, he writes: "Looking at pictures of naked girls in Penthouse is not exactly having a meaningful relationship with women. Eating carbohydrate snacks is not exactly having a meaningful relationship with food."

Structurally, however, the book threatens to become no more than an erratic composite of journalistic set pieces, laid out in bite-sized essays that you suspect could be reassembled in any order. And though Leith is at great pains to show us how he has suffered, there is a disaffecting dollop of complacency at the heart of the book - a weary air of too much casual sex, too many transatlantic flights, too many expensive coke binges - that less metropolitan readers may struggle to find much sympathy for.

Leith's account does carry a certain degree of originality, however, being the first neurotic splurge of body-image anxieties to be written by a man, though heaven knows what kind of floodgates it is likely to open - books about the trauma of going bald, books about the trauma of drinking too much beer, books about the trauma of maintaining the perfect abdomen? It could be that fatuousness is no longer a feminist issue.